1. Field of the Invention
The present disclosure relates to a rectifying device and a method for manufacturing the same, and more particulary, to an asymmetric rectifying device and a method for manufacturing the same.
2. Description of the Related Art
As a rectifying device having a rectifying property, there is a silicon or germanium diode using a p-n junction of a semiconductor, or a selenium rectifier or a copper oxide rectifier using the contact surface of the metal and the semiconductor. For example, there is a tunnel diode, etc.
Since the tunnel diode was invented by Esaki Leona, it has continuously received attention for half a century.
The tunnel diode is preferable for maintaining any switching state such as an open/closed state in many application fields, and a function of the tunnel diode is based on an interband tunneling of charge carriers.
For example, a tunnel diode is disclosed in Korean
Patent Publication No. 1995-0021729 entitled “tunnel diode and memory device”. In this tunnel diode, an insulating dielectric material is inserted between two conductive metal electrodes, forms a barrier having a barrier level for electrons and has a ferroelectric material layer at room temperature, in the tunnel diode having a degree of thickness such that electrons can tunnel through the barrier from one electrode to the other electrode at a voltage higher than a threshold voltage, and a current polarization of the dielectric material has a property in that it may vary the barrier level.
Also, a stacked solar cell having a tunnel diode layer is disclosed in Korean Patent Publication No. 2005-0065028 entitled “stacked solar cell having tunnel diode layer”. This stacked solar cell having the tunnel diode layer is configured to include a GaAlAs upper cell having a window layer on an upper surface on which light is incident, a GaAs lower cell to which a carrier generated in the GaAlAs upper cell transfers and a tunnel diode installed between the GaAlAs upper cell and the GaAs lower cell.
Further, a solar cell having a p-n tunnel diode is disclosed in Korean Patent No. 10-1105250 entitled “solar cell having p-n tunnel diode”. The solar cell having the p-n tunnel diode includes an n-type substrate, a p-n tunnel diode formed on the n-type substrate in which an n-type semiconductor and a p-type semiconductor are sequentially stacked to form a p-n junction, a photoelectric conversion cell formed on the p-n tunnel diode wherein the n-type semiconductor and the p-type semiconductor are sequentially stacked to convert a photo signal to a electrical signal, a lower electrode formed on a lower portion of the n-type substrate and an upper electrode formed on the photoelectric conversion cell, wherein the lower electrode and the upper electrode are n-ohmic contact electrodes.
In the tunnel diode such as that in this embodiment, when a voltage is applied across the junction and the tunnel diode is forward biased, as the voltage increases up to a peak voltage, a current increases up to a peak current, and if the voltage further increases up to a valley voltage, the current decreases up to a valley current.
However, the tunnel diode is considered to have a potential equal to a transistor, but does not actually have the potential in actual applications.
Using the tunnel diode has many potential advantages in many applications, but may limit application diversity because of insufficient performance due to the technical limits of a fabrication and a driving mechanism. Due to recent increases in data volume and communication frequencies, the development of a tunnel diode capable of operating in ultrahigh frequencies is required.